Lower-extremity joint kinematic coupling during side-step cutting manoeuvres

Abstract

The purpose of this study was to understand the lower extremity mechanics during a side-step cutting movement to explain the high rate of Anterior Cruciate Ligament (ACL) injuries associated with the movement. This was achieved through a contemporary joint coupling analysis with specific reference to knee and hip interaction when the cutting leg was changed. This was investigated through collection data with four participants (two males and two females) performing 10 trials over two cutting conditions. This was recorded by an online motion analysis system (200Hz) and exported to Microsoft Excel for further analysis. It was found that the left and right cutting condition produced different movement patterns when compared on an angle-angle graph of the knee and hip joints. It was also found that the right and left conditions produced different strategy biases when compared across a range of situations such as touchdown, toe-off, maximum knee flexion and corresponding hip angle. It was therefore concluded that there was a difference between left and right cutting conditions but it was inconclusive which leg was most predisposed to injury. Further research is required to establish the normal range of coupling as comparison against this would reveal a potentially injurious coupling